RAM Connection- HBBB- "web plate strength due to out of plane transverse load" failure

RAM is showing a failure for "web plate strength due to out of plane transverse load" but I do not believe it applies.  Below is a figure from the Design of Wrap Around Gussets paper referenced at the bottom of the results.  It shows there should be no out of plane loads applied to the beam or girder but that does not seem to be what RAM is doing.  Attached is the Connection Data and Design Report for reference.  Using V13 Upate 9.

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  • Can you send your file? I threw together a horizontal brace connection per AISC 36016 ASD and I'm not seeing that web plate check at all. I also have version 13.09. 



  • File uploaded. Filename HBBB. Spending further time investigating, the demand on the gusset-to-beam and gusset-to-girder connection changes significantly depending on whether it is directly welded or bolted.  

  • I see, that check is not even performed when the interface of the gusset to the beam/girder is bolted angles. I'll have to do some digging to find out why we implemented things differently. 



  • Some feedback from the Ram Conenction team: 

    When the user selects a directly welded connection for the HCBB Connection, we utilize the same design considerations as for a single plate connection in a Beam to Column configuration. This is due to their similar geometric and loading characteristics, and as a result, the capacities we are evaluating are based on the single plate design. The Web Plate Strength due out of plate transverse load capacity is included within the single plate design, which assumes a plate that remains continuously attached to the web of the supporting member. This approach only applies to directly welded connections. In instances where the connection is bolted, we follow the standard clip angle approach and assess all relevant capacities associated with that connection. Such capacities are available for BCF, BCW, BG, and gusset connections.



  • The response is concerning, it seems they are saying, “it’s like a shear tab, and we do that check for shear tabs, so we do it here too” without indicating any comprehension of the basis for the check.

    I think a review of the design process by the Ram Connection team is warranted, it does not seem to align with the design principles of the Uniform Force Method as applied in the Column-Beam-Brace connections.

    Referring back to the HBBB model I submitted:

    Given: Brace force is 55k, 47.63k is taken by the beam, 27.5k is taken by the girder.

    1) The Demand force being applied to the beam web in “Web plate strength due out of plate transverse load check” (27.5k) is the same as the load taken by the girder.  That does not appear correct and does not align with the Uniform Force Method.

    2) The Web plate strength due out of plate transverse load check” should be applied with bolted connections as well, see the Ram Connection Calculations for an all bolted Column-Beam-Brace connection.

  • Hello Doug,

    Let us answer both questions as follows

    1. We are using the simplified method, as recommended in the WRAP-AROUND GUSSET PLATES document by Bo Doswell, to determine the demands at each interface. This method involves calculating the demand for the girder and beam connections by using the axial load in the brace. Specifically, we use the component of the brace axial load that acts along the girder to obtain the demand at the girder connection, and the component of the brace axial load that acts perpendicular to the girder to obtain the demand at the beam connection.

    Using this method, we can obtain the demand for the web plate strength due to the out-of-plane transverse load check, which conservatively corresponds to this method. Specifically, the perpendicular load applied to the directly welded connector is the load component that acts perpendicular to the beam.

    2. You are correct about checking the Web plate strength due out of plate transverse load check for the clip angle connector (bolted connector). We will include the check in the next release.

     

Reply
  • Hello Doug,

    Let us answer both questions as follows

    1. We are using the simplified method, as recommended in the WRAP-AROUND GUSSET PLATES document by Bo Doswell, to determine the demands at each interface. This method involves calculating the demand for the girder and beam connections by using the axial load in the brace. Specifically, we use the component of the brace axial load that acts along the girder to obtain the demand at the girder connection, and the component of the brace axial load that acts perpendicular to the girder to obtain the demand at the beam connection.

    Using this method, we can obtain the demand for the web plate strength due to the out-of-plane transverse load check, which conservatively corresponds to this method. Specifically, the perpendicular load applied to the directly welded connector is the load component that acts perpendicular to the beam.

    2. You are correct about checking the Web plate strength due out of plate transverse load check for the clip angle connector (bolted connector). We will include the check in the next release.

     

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